Two Wire Interface Master with EasyDMA (TWIM) peripheral driver.
More...
|
#define | NRFX_TWIM_INSTANCE(id) |
| Macro for creating a TWI master driver instance. More...
|
|
#define | NRFX_TWIM_DEFAULT_CONFIG |
| TWI master driver instance default configuration. More...
|
|
#define | NRFX_TWIM_FLAG_TX_POSTINC (1UL << 0) |
| Flag indicating that TX buffer address will be incremented after the transfer.
|
|
#define | NRFX_TWIM_FLAG_RX_POSTINC (1UL << 1) |
| Flag indicating that RX buffer address will be incremented after the transfer.
|
|
#define | NRFX_TWIM_FLAG_NO_XFER_EVT_HANDLER (1UL << 2) |
| Flag indicating that the interrupt after each transfer will be suppressed, and the event handler will not be called.
|
|
#define | NRFX_TWIM_FLAG_HOLD_XFER (1UL << 3) |
| Flag indicating that the transfer will be set up, but not started.
|
|
#define | NRFX_TWIM_FLAG_REPEATED_XFER (1UL << 4) |
| Flag indicating that the transfer will be executed multiple times.
|
|
#define | NRFX_TWIM_FLAG_TX_NO_STOP (1UL << 5) |
| Flag indicating that the TX transfer will not end with a stop condition.
|
|
#define | NRFX_TWIM_FLAG_NO_SPURIOUS_STOP_CHECK (1UL << 6) |
| Flag indicating that checks for spurious STOP condition will not be performed.
|
|
#define | NRFX_TWIM_XFER_DESC_TX(addr, p_data, length) |
| Macro for setting the TX transfer descriptor. More...
|
|
#define | NRFX_TWIM_XFER_DESC_RX(addr, p_data, length) |
| Macro for setting the RX transfer descriptor. More...
|
|
#define | NRFX_TWIM_XFER_DESC_TXRX(addr, p_tx, tx_len, p_rx, rx_len) |
| Macro for setting the TX-RX transfer descriptor. More...
|
|
#define | NRFX_TWIM_XFER_DESC_TXTX(addr, p_tx, tx_len, p_tx2, tx_len2) |
| Macro for setting the TX-TX transfer descriptor. More...
|
|
|
nrfx_err_t | nrfx_twim_init (nrfx_twim_t const *p_instance, nrfx_twim_config_t const *p_config, nrfx_twim_evt_handler_t event_handler, void *p_context) |
| Function for initializing the TWI driver instance. More...
|
|
void | nrfx_twim_uninit (nrfx_twim_t const *p_instance) |
| Function for uninitializing the TWI instance. More...
|
|
void | nrfx_twim_enable (nrfx_twim_t const *p_instance) |
| Function for enabling the TWI instance. More...
|
|
void | nrfx_twim_disable (nrfx_twim_t const *p_instance) |
| Function for disabling the TWI instance. More...
|
|
nrfx_err_t | nrfx_twim_tx (nrfx_twim_t const *p_instance, uint8_t address, uint8_t const *p_data, size_t length, bool no_stop) |
| Function for sending data to a TWI slave. More...
|
|
nrfx_err_t | nrfx_twim_rx (nrfx_twim_t const *p_instance, uint8_t address, uint8_t *p_data, size_t length) |
| Function for reading data from a TWI slave. More...
|
|
nrfx_err_t | nrfx_twim_xfer (nrfx_twim_t const *p_instance, nrfx_twim_xfer_desc_t const *p_xfer_desc, uint32_t flags) |
| Function for performing a TWI transfer. More...
|
|
bool | nrfx_twim_is_busy (nrfx_twim_t const *p_instance) |
| Function for checking the TWI driver state. More...
|
|
uint32_t | nrfx_twim_start_task_get (nrfx_twim_t const *p_instance, nrfx_twim_xfer_type_t xfer_type) |
| Function for returning the address of a TWIM start task. More...
|
|
uint32_t | nrfx_twim_stopped_event_get (nrfx_twim_t const *p_instance) |
| Function for returning the address of a STOPPED TWIM event. More...
|
|
__STATIC_INLINE nrfx_err_t | nrfx_twim_bus_recover (uint32_t scl_pin, uint32_t sda_pin) |
| Function for recovering the bus. More...
|
|
Two Wire Interface Master with EasyDMA (TWIM) peripheral driver.
#define NRFX_TWIM_DEFAULT_CONFIG |
Value:{ \
.scl = 31, \
.sda = 31, \
}
TWI master driver instance default configuration.
#define NRFX_TWIM_INSTANCE |
( |
|
id | ) |
|
Value:
Macro for creating a TWI master driver instance.
#define NRFX_TWIM_XFER_DESC_RX |
( |
|
addr, |
|
|
|
p_data, |
|
|
|
length |
|
) |
| |
Value:{ \
.address = (addr), \
.primary_length = (length), \
.secondary_length = 0, \
.p_primary_buf = (p_data), \
.p_secondary_buf = NULL, \
}
Macro for setting the RX transfer descriptor.
#define NRFX_TWIM_XFER_DESC_TX |
( |
|
addr, |
|
|
|
p_data, |
|
|
|
length |
|
) |
| |
Value:{ \
.address = (addr), \
.primary_length = (length), \
.secondary_length = 0, \
.p_primary_buf = (p_data), \
.p_secondary_buf = NULL, \
}
Macro for setting the TX transfer descriptor.
#define NRFX_TWIM_XFER_DESC_TXRX |
( |
|
addr, |
|
|
|
p_tx, |
|
|
|
tx_len, |
|
|
|
p_rx, |
|
|
|
rx_len |
|
) |
| |
Value:{ \
.address = (addr), \
.primary_length = (tx_len), \
.secondary_length = (rx_len), \
.p_primary_buf = (p_tx), \
.p_secondary_buf = (p_rx), \
}
Macro for setting the TX-RX transfer descriptor.
#define NRFX_TWIM_XFER_DESC_TXTX |
( |
|
addr, |
|
|
|
p_tx, |
|
|
|
tx_len, |
|
|
|
p_tx2, |
|
|
|
tx_len2 |
|
) |
| |
Value:{ \
.address = (addr), \
.primary_length = (tx_len), \
.secondary_length = (tx_len2), \
.p_primary_buf = (p_tx), \
.p_secondary_buf = (p_tx2), \
}
Macro for setting the TX-TX transfer descriptor.
TWI master driver event types.
Enumerator |
---|
NRFX_TWIM_EVT_DONE |
Transfer completed event.
|
NRFX_TWIM_EVT_ADDRESS_NACK |
Error event: NACK received after sending the address.
|
NRFX_TWIM_EVT_DATA_NACK |
Error event: NACK received after sending a data byte.
|
NRFX_TWIM_EVT_OVERRUN |
Error event: The unread data is replaced by new data.
|
NRFX_TWIM_EVT_BUS_ERROR |
Error event: An unexpected transition occurred on the bus.
|
TWI master driver transfer types.
Enumerator |
---|
NRFX_TWIM_XFER_TX |
TX transfer.
|
NRFX_TWIM_XFER_RX |
RX transfer.
|
NRFX_TWIM_XFER_TXRX |
TX transfer followed by RX transfer with repeated start.
|
NRFX_TWIM_XFER_TXTX |
TX transfer followed by TX transfer with repeated start.
|
__STATIC_INLINE nrfx_err_t nrfx_twim_bus_recover |
( |
uint32_t |
scl_pin, |
|
|
uint32_t |
sda_pin |
|
) |
| |
Function for recovering the bus.
This function checks if the bus is not stuck because of a slave holding the SDA line in the low state, and if needed it performs required number of pulses on the SCL line to make the slave release the SDA line. Finally, the function generates a STOP condition on the bus to put it into a known state.
- Note
- This function can be used only if the TWIM driver is uninitialized.
- Parameters
-
[in] | scl_pin | SCL pin number. |
[in] | sda_pin | SDA pin number. |
- Return values
-
NRFX_SUCCESS | Bus recovery was successful. |
NRFX_ERROR_INTERNAL | Bus recovery failed. |
void nrfx_twim_disable |
( |
nrfx_twim_t const * |
p_instance | ) |
|
Function for disabling the TWI instance.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
void nrfx_twim_enable |
( |
nrfx_twim_t const * |
p_instance | ) |
|
Function for enabling the TWI instance.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
Function for initializing the TWI driver instance.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
[in] | p_config | Pointer to the structure with the initial configuration. |
[in] | event_handler | Event handler provided by the user. If NULL, blocking mode is enabled. |
[in] | p_context | Context passed to event handler. |
- Return values
-
NRFX_SUCCESS | Initialization was successful. |
NRFX_ERROR_INVALID_STATE | The driver is in invalid state. |
NRFX_ERROR_BUSY | Some other peripheral with the same instance ID is already in use. This is possible only if Peripheral Resource Sharing (PRS) module is enabled. |
bool nrfx_twim_is_busy |
( |
nrfx_twim_t const * |
p_instance | ) |
|
Function for checking the TWI driver state.
- Parameters
-
[in] | p_instance | TWI instance. |
- Return values
-
true | The TWI driver is currently busy performing a transfer. |
false | The TWI driver is ready for a new transfer. |
nrfx_err_t nrfx_twim_rx |
( |
nrfx_twim_t const * |
p_instance, |
|
|
uint8_t |
address, |
|
|
uint8_t * |
p_data, |
|
|
size_t |
length |
|
) |
| |
Function for reading data from a TWI slave.
The transmission will be stopped when an error occurs. If a transfer is ongoing, the function returns the error code NRFX_ERROR_BUSY.
- Note
- This function is deprecated. Use nrfx_twim_xfer instead.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
[in] | address | Address of a specific slave device (only 7 LSB). |
[in] | p_data | Pointer to a receive buffer. |
[in] | length | Number of bytes to be received. Maximum possible length is dependent on the used SoC (see the MAXCNT register description in the Product Specification). The driver checks it with assertion. |
- Return values
-
NRFX_SUCCESS | The procedure is successful. |
NRFX_ERROR_BUSY | The driver is not ready for a new transfer. |
NRFX_ERROR_INTERNAL | An unexpected transition occurred on the bus. |
NRFX_ERROR_DRV_TWI_ERR_OVERRUN | The unread data is replaced by new data. |
NRFX_ERROR_DRV_TWI_ERR_ANACK | NACK is received after sending the address in polling mode. |
NRFX_ERROR_DRV_TWI_ERR_DNACK | NACK is received after sending a data byte in polling mode. |
Function for returning the address of a TWIM start task.
This function is to be used if nrfx_twim_xfer was called with the flag NRFX_TWIM_FLAG_HOLD_XFER. In that case, the transfer is not started by the driver, but it must be started externally by PPI.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
[in] | xfer_type | Transfer type used in the last call of the nrfx_twim_xfer function. |
- Returns
- Start task address (TX or RX) depending on the value of xfer_type.
uint32_t nrfx_twim_stopped_event_get |
( |
nrfx_twim_t const * |
p_instance | ) |
|
Function for returning the address of a STOPPED TWIM event.
A STOPPED event can be used to detect the end of a transfer if the NRFX_TWIM_FLAG_NO_XFER_EVT_HANDLER option is used.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
- Returns
- STOPPED event address.
nrfx_err_t nrfx_twim_tx |
( |
nrfx_twim_t const * |
p_instance, |
|
|
uint8_t |
address, |
|
|
uint8_t const * |
p_data, |
|
|
size_t |
length, |
|
|
bool |
no_stop |
|
) |
| |
Function for sending data to a TWI slave.
The transmission will be stopped when an error occurs. If a transfer is ongoing, the function returns the error code NRFX_ERROR_BUSY.
- Note
- This function is deprecated. Use nrfx_twim_xfer instead.
-
Peripherals using EasyDMA (including TWIM) require the transfer buffers to be placed in the Data RAM region. If this condition is not met, this function fails with the error code NRFX_ERROR_INVALID_ADDR.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
[in] | address | Address of a specific slave device (only 7 LSB). |
[in] | p_data | Pointer to a transmit buffer. |
[in] | length | Number of bytes to send. Maximum possible length is dependent on the used SoC (see the MAXCNT register description in the Product Specification). The driver checks it with assertion. |
[in] | no_stop | If set, the stop condition is not generated on the bus after the transfer has completed successfully (allowing for a repeated start in the next transfer). |
- Return values
-
NRFX_SUCCESS | The procedure is successful. |
NRFX_ERROR_BUSY | The driver is not ready for a new transfer. |
NRFX_ERROR_INTERNAL | An unexpected transition occurred on the bus. |
NRFX_ERROR_INVALID_ADDR | The provided buffer is not placed in the Data RAM region. |
NRFX_ERROR_DRV_TWI_ERR_ANACK | NACK is received after sending the address in polling mode. |
NRFX_ERROR_DRV_TWI_ERR_DNACK | NACK is received after sending a data byte in polling mode. |
void nrfx_twim_uninit |
( |
nrfx_twim_t const * |
p_instance | ) |
|
Function for uninitializing the TWI instance.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
Function for performing a TWI transfer.
The following transfer types can be configured (nrfx_twim_xfer_desc_t::type):
- Note
- TX-RX and TX-TX transfers are supported only in non-blocking mode.
Additional options are provided using the flags parameter:
- Note
- Some flag combinations are invalid:
If nrfx_twim_xfer_desc_t::type is set to NRFX_TWIM_XFER_TX and the NRFX_TWIM_FLAG_TX_NO_STOP and NRFX_TWIM_FLAG_REPEATED_XFER flags are set, two tasks must be used to trigger a transfer: TASKS_RESUME followed by TASKS_STARTTX. If no stop condition is generated, TWIM is in SUSPENDED state. Therefore, it must be resumed before the transfer can be started.
- Note
- Peripherals using EasyDMA (including TWIM) require the transfer buffers to be placed in the Data RAM region. If this condition is not met, this function will fail with the error code NRFX_ERROR_INVALID_ADDR.
- Parameters
-
[in] | p_instance | Pointer to the driver instance structure. |
[in] | p_xfer_desc | Pointer to the transfer descriptor. |
[in] | flags | Transfer options (0 for default settings). |
- Return values
-
NRFX_SUCCESS | The procedure is successful. |
NRFX_ERROR_BUSY | The driver is not ready for a new transfer. |
NRFX_ERROR_NOT_SUPPORTED | The provided parameters are not supported. |
NRFX_ERROR_INTERNAL | An unexpected transition occurred on the bus. |
NRFX_ERROR_INVALID_ADDR | The provided buffers are not placed in the Data RAM region. |
NRFX_ERROR_DRV_TWI_ERR_OVERRUN | The unread data is replaced by new data. |
NRFX_ERROR_DRV_TWI_ERR_ANACK | NACK is received after sending the address. |
NRFX_ERROR_DRV_TWI_ERR_DNACK | NACK is received after sending a data byte. |